Battery self-heating device and vehicle

Abstract

A battery self-heating device includes a battery self-heating circuit and a controller. The battery self-heating circuit includes a first battery group, a second battery group, a bridge arm, and a winding corresponding to the bridge arm. A negative electrode of the first battery group and a positive electrode of the second battery group are connected to each other, and are connected to an output end of the winding. An input end of the winding is connected to a midpoint of the bridge arm. A positive electrode of the first battery group is connected to a first bus end of the bridge arm. A negative electrode of the second battery group is connected to a second bus end of the bridge arm. The controller is configured to adjust the duty ratio of the bridge arm according to a target duty ratio range.

What is claimed is: 
     
         1 . A battery self-heating device, comprising a battery self-heating circuit and a controller,
 the battery self-heating circuit comprising a first battery group, a second battery group, a bridge arm, and a winding corresponding to the bridge arm;
 a negative electrode of the first battery group connected to a positive electrode of the second battery group, the negative electrode of the first battery group and the positive electrode of the second battery group connected to an output end of the winding, and an input end of the winding connected to a midpoint of the bridge arm; 
 a positive electrode of the first battery group connected to a first bus end of the bridge arm, and a negative electrode of the second battery group connected to a second bus end of the bridge arm; and 
 in response to detecting that the battery self-heating circuit is in an operating state, the controller configured to adjust a duty ratio of the bridge arm according to a target duty ratio range to configure a fundamental frequency of a heating current of the battery self-heating circuit to change within a target fundamental frequency range, and the target duty ratio range obtained according to a mapping relationship between the fundamental frequency and the duty ratio. 
   
     
     
         2 . The battery self-heating device according to  claim 1 , wherein the controller is configured to,
 within a duration, select a target duty ratio from the target duty ratio range, and adjust the duty ratio of the bridge arm according to the target duty ratio to configure the fundamental frequency of the heating current to change within the target fundamental frequency range.   
     
     
         3 . The battery self-heating device according to  claim 1 , wherein the controller is configured to,
 within a duration, sequentially adjust the duty ratio of the bridge arm to a first lower limit, a first upper limit, and the first lower limit according to the target duty ratio range, to configure the fundamental frequency of the heating current to a second lower limit, a second upper limit, and the second lower limit sequentially,   wherein the first lower limit and the first upper limit are obtained according to the target duty ratio range, and the second lower limit and the second upper limit are obtained according to the target fundamental frequency range.   
     
     
         4 . The battery self-heating device according to  claim 1 , wherein the controller is configured to:
 obtain a time-domain waveform of the heating current, the time-domain waveform indicating a change of the heating current in time domain;   perform a Fourier transform on the time-domain waveform to obtain a frequency-domain waveform, the frequency-domain waveform indicating a change of the heating current in frequency domain; and   adjust the duty ratio of the bridge arm according to a noise amplitude in the frequency-domain waveform, to adjust the fundamental frequency of the heating current.   
     
     
         5 . The battery self-heating device according to  claim 1 , wherein the bridge arm is a multi-phase bridge arm comprising a plurality of phase bridge arms, the winding is a multi-phase winding comprising a plurality of phase windings, each of the phase windings corresponds to one of the phase bridge arms, and each of the phase windings is connected to a midpoint of the corresponding bridge arm. 
     
     
         6 . The battery self-heating device according to  claim 1 , wherein:
 the battery self-heating circuit further comprises a first capacitor and a second capacitor; and   a first end of the second capacitor is connected to a second end of the first capacitor, the first end of the second capacitor and the second end of the first capacitor are connected to the output end of the winding, a second end of the second capacitor is connected to the negative electrode of the second battery group, and a first end of the first capacitor is connected to the positive electrode of the first battery group.   
     
     
         7 . The battery self-heating device according to  claim 6 , wherein the battery self-heating circuit further comprises a first switch, and the first end of the second capacitor and the second end of the first capacitor are connected to the output end of the winding through the first switch. 
     
     
         8 . The battery self-heating device according to  claim 1 , wherein the battery self-heating circuit further comprises a second switch, and the negative electrode of the first battery group and the positive electrode of the second battery group are connected to the output end of the winding through the second switch. 
     
     
         9 . The battery self-heating device according to  claim 1 , wherein the winding is in a motor of a vehicle, and the bridge arm is a bridge arm switch configured to control the motor in the vehicle. 
     
     
         10 . The battery self-heating device according to  claim 1 , wherein the battery self-heating circuit further comprises a direct-current (DC) charging port, the output end of the winding is connected to a positive electrode of the DC charging port, and a second bus end of the bridge arm is connected to a negative electrode of the DC charging port. 
     
     
         11 . The battery self-heating device according to  claim 10 , wherein the battery self-heating circuit further comprises a third switch, the first bus end of the bridge arm is connected to a first end of the third switch, and a second end of the third switch is connected to the positive electrode of the DC charging port. 
     
     
         12 . A vehicle, comprising a battery self-heating device, the battery self-heating device comprising a battery self-heating circuit and a controller,
 the battery self-heating circuit comprising a first battery group, a second battery group, a bridge arm, and a winding corresponding to the bridge arm;
 a negative electrode of the first battery group connected to a positive electrode of the second battery group, the negative electrode of the first battery group and the positive electrode of the second battery group connected to an output end of the winding, and an input end of the winding connected to a midpoint of the bridge arm; 
 a positive electrode of the first battery group connected to a first bus end of the bridge arm, and a negative electrode of the second battery group connected to a second bus end of the bridge arm; and 
 in response to detecting that the battery self-heating circuit is in an operating state, the controller configured to adjust a duty ratio of the bridge arm according to a target duty ratio range to configure a fundamental frequency of a heating current of the battery self-heating circuit to change within a target fundamental frequency range, and the target duty ratio range obtained according to a mapping relationship between the fundamental frequency and the duty ratio. 
   
     
     
         13 . The vehicle according to  claim 12 , wherein the controller is configured to,
 within a duration, select a target duty ratio from the target duty ratio range, and adjust the duty ratio of the bridge arm according to the target duty ratio to configure the fundamental frequency of the heating current to change within the target fundamental frequency range.   
     
     
         14 . The vehicle according to  claim 12 , wherein the controller is configured to,
 within a duration, sequentially adjust the duty ratio of the bridge arm to a first lower limit, a first upper limit, and the first lower limit according to the target duty ratio range, to configure the fundamental frequency of the heating current to a second lower limit, a second upper limit, and the second lower limit sequentially,   wherein the first lower limit and the first upper limit are obtained according to the target duty ratio range, and the second lower limit and the second upper limit are obtained according to the target fundamental frequency range.   
     
     
         15 . The vehicle according to  claim 12 , wherein the controller is configured to:
 obtain a time-domain waveform of the heating current, the time-domain waveform indicating a change of the heating current in time domain;   perform a Fourier transform on the time-domain waveform to obtain a frequency-domain waveform, the frequency-domain waveform indicating a change of the heating current in frequency domain; and   adjust the duty ratio of the bridge arm according to a noise amplitude in the frequency-domain waveform, to adjust the fundamental frequency of the heating current.   
     
     
         16 . The vehicle according to  claim 12 , wherein the bridge arm is a multi-phase bridge arm comprising a plurality of phase bridge arms, the winding is a multi-phase winding comprising a plurality of phase windings, each of the phase windings corresponds to one of the phase bridge arms, and each of the phase windings is connected to a midpoint of the corresponding bridge arm. 
     
     
         17 . The vehicle according to  claim 12 , wherein:
 the battery self-heating circuit further comprises a first capacitor and a second capacitor; and   a first end of the second capacitor is connected to a second end of the first capacitor, the first end of the second capacitor and the second end of the first capacitor are connected to the output end of the winding, a second end of the second capacitor is connected to the negative electrode of the second battery group, and a first end of the first capacitor is connected to the positive electrode of the first battery group.   
     
     
         18 . The vehicle according to  claim 17 , wherein the battery self-heating circuit further comprises a first switch, and the first end of the second capacitor and the second end of the first capacitor are connected to the output end of the winding through the first switch. 
     
     
         19 . The vehicle according to  claim 12 , wherein the battery self-heating circuit further comprises a second switch, and the negative electrode of the first battery group and the positive electrode of the second battery group are connected to the output end of the winding through the second switch. 
     
     
         20 . The vehicle according to  claim 12 , wherein the winding is in a motor of a vehicle, and the bridge arm is a bridge arm switch configured to control the motor in the vehicle.